We In Sinful Rapture
by Natsumiya Teirin
Summary: In an attempt to teach her lovers a lesson in self-restraint, Kagamine Rin enlists the help of Meiko the fate, and journeys through multiple worlds. But Miku and Luka aren't the only ones chasing her, as an unwitting identity theft throws Gakupo and Kaito after her, too! Lots of yuri, some yaoi, VanaN'Ice ship and NegiOraToro.
1. Chapter 1

The glass frame beside her shattered with the force of Luka's hand against the wall upon which it hung.

"Why?! I've done everything for you, so why do you not love me!?"

Frightened blue eyes peered meekly up at her, apologetic and sorrowful, and she hated it and at the same time loved the girl to bits and pieces.

It was a love so deep and strong as to be overwhelming- all-consuming to the point of insanity.

She wanted- _needed_ \- those eyes to look only at her. She needed that voice to speak only to her.

But for her most precious person to even be speaking to that blonde-haired witch Lily...

Was unforgivable.

If Rin could be turned away from her so easily, then she was better off dead. Then, no one could ever take her away.

Before she was fully aware of it, Luka wrapped her hands around Rin's neck, not even caring that the younger, smaller girl wasn't even struggling. As far as Rin was concerned, this was a routine thing. But Luka just didn't get it yet.

Those slim, pale hands squeezed, crushing her windpipe and cutting off her airway.

Rin's vision faded, spotting before going completely black.

There was a kaleidoscope of color then, reds and purples and blues, and then she was on a staircase of white marble in the middle of a red void. At the top was Meiko the fate, dressed in her favored red armor, clutching her golden longsword in her right hand.

"So...they've done it again, haven't they?"

Rin nodded her head and walked slowly up the long staircase. "Yes, they have."

Meiko hummed thoughtfully.

"Hatsune Miku and Megurine Luka...the highest of the elves and the queen of the Fae...you know, most mortals would consider themselves most fortunate to earn their love..."

The brunette licked her lips to moisten them.

"I wonder why you do not..."

Rin paused in her step momentarily, realizing.

"That's why I've never been able to pass on, isn't it?"

Meiko smirked.

"Yes. Clever girl, you are. However, I, too, have grown attached."

Rin hummed and finally reached the top, coming to stand before her.

"Will you now allow me to pass? I grow weary of dying for every slight offense, and though I _do_ love those two, I wish not to die by their hands again."

"Is this truly what you wish?" Meiko asked, tilting her head, "Will this make you happy?"

Rin nodded her head.

"Yes. Allow them to pursue if they so wish, but allow me to leave this world and pass on to the next, and the one after that, and so on, till they realize their mistakes- I implore you, Fate!"

Meiko nodded and stepped to the side. She swung her sword to the opposite side and watched as _The Gate_ opened, the blue void contrasting beautifully against the red and white of her domain.

"I will not be able to guard you as carefully as I could here," she warned, "but I will ask my other variants to do what they can for you."

Rin stepped forward, the Gate casting its majorelle glow across her pale face.

"Now, go. Go and be safe. I will see to it that Miku and Luka follow after you."

With one last, thankful look towards Meiko, Rin stepped through _The Gate_.

 _OooOooOooOooO_

 _It's...white._

Rin woke up to a white ceiling, darkened in places untouched by the morning light shining through the window beside her bed. This was something familiar to her, but only vaguely. It had been a long time since she'd been in the modern world.

With a groan, she rolled out of bed and examined her surroundings further. Right next to her current spot on the floor was a low coffee table, and to the left of that was a bookshelf. Across from her was a short hallway leading up to a door- presumably the front door. She stood up and saw that atop the coffee table was a vase of daffodils, and beside that a mobile phone. She began walking and found that right around the corner of her bed was a small kitchenette, and then a half-bathroom, with only a sink and toilet. Across from that was a tiny closet with only a couple coats and a purse.

An apartment.

It'd been many years since she'd seen the inside of a modern apartment.

Suddenly nostalgic, Rin walked over to the bookshelf and grabbed a random book. She turned to the latest entry and began silently reading.

 _ **August 4th, 2015**_

 _It's been a few years now since Gumi-kun and I started dating. In hindsight, it's a little funny how that happened. Or maybe 'cliché' is a better word. I still have the love-letter she sent me hidden away in my purse. I like to read it to myself every now and then, when she leaves me alone to go to her classes. It's comforting. She's going to come over tomorrow to walk me to work, and even after so long, I can barely restrain myself just thinking about it! Aahh, what a wonderful way to begin my first day of work!_

A diary.

Rin flipped back to the first page.

 _ **March 23rd, 2015**_

 _Hello again diary._

 _Though you're new-to-me, and I'll probably continue where the last diary left off, so I'll re-introduce myself._

 _My name is Kagamine Rin. I'm 22 years old and I attend a university in Hokkaido. My girlfriend Gumi-kun says I'm usually very cheerful and cute, but I'm not so sure that's true._

 _Well, that's all I have for now. I'll write to you again tomorrow night._

 _Till then, diary._

So, she was replacing this world's version of herself...?

Strange as it was, she couldn't think of any other way for this to work. It'd only be troublesome if there were two Rins running around.

The phone rang (a very cheery and upbeat chime, Rin noted, or maybe it had just been too long since she'd been around such things) and Rin quickly got it, noticing that the screen (which lit up as soon as she touched it) displayed a new message.

 **From: Gumi-kun**

 **Ohayou Rin-chan! Are you up yet? I'll be there in an hour, and if you're still sleeping I'll mercilessly tickle you awake!**

An hour...that should be enough time to get ready, right?

Except...Rin didn't know what she was required to wear to work. There wasn't anything resembling a professional uniform in the apartment, so either she hadn't gotten one yet, or she was expected to change once she got there.

In either case she supposed it didn't matter too much what she wore. The Rin of this world seemed to dress nicely all the time. Silently praying- to all the fae and elven gods as well as what human ones she remembered- for the day to go well, Rin changed into a white dress shirt and black slacks. She slid into a black sweater vest and tied a yellow ribbon around the collar of her shirt. Figuring she wouldn't have time for a big breakfast, Rin combed her hair and tied a floppy white bow into it, then grabbed an apple from a fruit basket in the kitchen and began eating it.

She woke up instantly, feeling more aware as the natural sugars of the apple juice rejuvenated her system.

There was a knock on the door, and Rin remembered what she read in the diary.

 _My girlfriend Gumi-kun says I'm usually very cheerful and cute._

Then all she needed to do was try to act cheerful, right? It wouldn't be good for this 'Gumi-kun' to find out her Rin was being temporarily replaced. Not only would Rin herself feel bad, but Gumi might also try to hurt her out of fear and worry for this world's Rin, or else think she'd lost her mind and have her committed into an asylum, and that wouldn't be good either.

 _No...no...don't panic...not now. Just...stay calm. Stay calm and act cheery, so she doesn't suspect._

She opened the door.

 _OooOooOooOooO_

"You killed her _again_!?"

Miku's voice was angry, and for just a split second, Luka felt guilty. She brushed it aside.

 _It's all Lily's fault! She_ knew _Rin belonged to me!_

Miku was still glaring at her, but Luka noticed half her attention was on Rin's corpse, lying still in the bed.

"It's fine, Miku. It was all _Lily's_ fault anyway, trying to take her away from me- from _us_. I had to make her think Rin was dead so she'd leave her alone."

The faery queen's gaze intensified.

"Then why hasn't she come back? It's taken a full day for me to get the news, and then another two for me to get here. Meiko usually has her back in a few hours, at most! And _never_ more than a day!"

She was really angry now, and a small part of Luka felt glad to induce such an ugly emotion.

"If she's _still_ not back," began Miku threateningly, " then it's not likely she ever _will_ come back! Don't you _get it_!?"

She took a menacing step forward, raw, unadulterated magic crackling at her fingertips.

" _You. Fucked. Up._ You fucked up _royally_ , and now Meiko's taken her away for good!"

Luka huffed, hardly phased.

"Then all we have to do is get her back, right? We're both immortal anyway, so we can just pop on in, grab Rin, and come back. Easy."

Miku stilled.

"It's not so easy," she bit out.

"We'd be facing the embodiment of _fate_ , Luka! Or have you forgotten? She's responsible for bringing her back to us every time she dies at all!"

Luka tsk'd.

"But Miku, we're _immortal_ , or have you forgotten?" Her tone was mocking, " we still have preordained futures, but death was never written in our fates, and Meiko knows that. So," she raised her hand a drew a tri-pointed star in the air, "let's go already. The sooner we leave, the sooner we can get Rin back and apologize for being so careless." _Again_.

Miku humphed but mirrored Luka's hand gesture. "Fine. But this next week, she's staying with me."

A hole opened up in the fabric of space, exposing Miku the Fae Queen and Luka the Elfin Bereth to the red void that was Fate's domain.

As they entered, the void closed, leaving no trace that anything had happened.

Miku and Luka walked together up the white marble stairs, determination in their steps and fire in their eyes. At the top, they witnessed Meiko snip a thin, silvery thread from the end of a golden spinning wheel. She was still dressed in her red armor, and her longsword was sheathed and strapped to her hip, angled against the floor as the deity knelt before the wheel.

"Miku. Luka." She addressed them without turning to face them.

"I've been expecting you."

"Then you must also know why we have come," Miku stated curtly.

"Yes, I know exactly why you are here, but..." they could hear the smirk in her voice, " humor an old spirit. Why have you entered my domain? Have you really missed our weekly tea parties so much?"

Luka growled. She'd forgotten how much Meiko got on her nerves.

"What have you done with Rin?!" She demanded, her voice echoing around them.

Meiko gave a dismissive wave of her hand, her brown eyes only half-sympathetic.

"I did what she asked of me. I opened _The Gate_ and allowed her to pass on to another universe." Miku and Luka both heard the italics in that statement, though Meiko's tone wasn't exactly emphatic.

"Explain," Miku ordered, before Luka could go off.

"She was tired of _you two_ -" her voice was very emphatic now "-killing her in your horrific temper tantrums. So she asked me to grant her travel through other universes so you'd learn your lesson."

Before either of them could make some angry remark, she continued, " you may follow her if you wish, but she won't return to you so willingly."

Luka was eager.

"So we can still get her back then? Great! Let's go!"

"H-Hey! Hold on, elf! Didn't you hear? Rin might not even _want_ to come back with us!" Miku argued.

" _Of course_ I heard, Queenie. I never said she'd want to- but I want- no, I _need_ her back by my side, so I'm gonna chase after her and drag her back to the Othrond kicking and screaming if I have to! Come with me if you want!" She took three large, determined steps until she was staring down at the back of Meiko's head. The woman already had her hand on the hilt of her sword.

"Meiko!" Luka barked. "Open _The Gate_!"

Once again, Miku heard the italics despite the lack of emphasis in Luka's tone.

Meiko chuckled.

"As you wish, Elfin Bereth."

She stood and drew her sword, and Luka stepped back to avoid getting cut by the blade. Meiko swept her sword to the side and the blue void- _The Gate_ leading from one universe to the next in an infinite cycle- glowed across the pink-haired elf's face. Luka jumped through it without hesitation, and Miku waited a moment to make up her mind before following.

Meiko watched them and sighed as _The Gate_ closed.

"...A goodbye would've been nice...or even a thank you..."

But the soul she'd severed from the mortal plane had automatically been sent to Gumi for judgement, due to her automated system.

There was only the silence of the red void.


	2. Chapter 2

Mortal eyes were not permitted to gaze upon the true passageway which linked universes together. As she and Luka walked through the void of swirling greens and yellows, upon an invisible walkway, Miku could only imagine what Rin might've seen.

Maybe she saw blue, like _The Gate_. Or maybe she didn't see anything, and passed through it in literal blindness. Maybe she didn't even pass through it, but fell, as if through a hole, and ended up in the next universe as if she'd woken from a dream.

But she was _im_ mortal, so she'd never know for sure. And Rin was odd to begin with, among humans. She had magic- not enough to cast any high level spells, but maybe a basic levitation spell, or a weak defensive spell, but the _magic was still there_ , and it was enough to allow her to see and interact with the magic world- the world of Fae and Elves and Goblins and Mermaids and other fantastical creatures- that had existed parallel to the world she knew.

It was that magic which had drawn them to her- to the human who was never fated to have even that much magic, but did- and it was she who had unintentionally infatuated both her and Luka in her attempts to learn all that she could of their world.

Miku tuned out the soft clicking of Luka's heeled steps (really, those bright yellow and earthy brown boots did not suit her at all, nevermind that Rin had made them for her) and kept her gaze forward. They were approaching something. What was it?

As they got closer, Miku, with her magically-enhanced sight, saw that it was a door. A white one marked with one of the two sun symbols.

"A circle with a dot inside it..." Luka mused, putting a finger to her chin. "I think it's an older astrological symbol, but I'm not entirely sure..." she shrugged. She only remembered the more recent signs taught to her in her astronomy lessons. Miku, who had been around longer and actually remembered more of her lessons, chose not to comment, and instead reached her hand towards the shimmering red knob.

She twisted, and the door opened, and suddenly they were on the rooftop of some sort of building. It was something unfamiliar to both of them, this place of concrete and metal. But the iron made Miku feel nauseous.

"I can't sense any magic here..." she breathed, trying to ease herself. Luka hummed. The elves were naturally best in areas full of natural materials- including ores and metals. As a result, the iron didn't affect her as it did Miku.

"Well, even if you could, it wouldn't make much difference. There isn't much magic to be sensed. However, I _do_ sense a small amount. And I'm _fairly certain_ that what I'm sensing is _Rin's_ magic."

Thinking of the blonde human helped to settle the churning in her gut.

"Then, let's go find her. What direction is she in?"

Luka closed her eyes and focused, trying to pinpoint Rin's location. But the manmade elements in the area made it difficult to get it precise.

"I can't get an exact reading, but...I think she's somewhere below us..."

 _OooOooOooOooO_

At the entrance to Yuzuki's Bath House, if one were to look to their right-hand side, they'd see a set of descending stairs. If they were so inclined to follow those stairs, whether after or before bathing, they'd come to a simple oaken door with a bronze knob. And to the left of that door, on a shining golden plaque, was the name of this establishment.

伝統党

The Traditional Party, helpfully translated below, for English tourists.

The interior of the café was a soothing mix of reds, blues, and yellows. Perhaps if the establishment had been aboveground, it would've been a bit less so, but as it was, Dento-To (written as 伝統党) was underground, so everything was a little dimmer, lit only by lamps and conveniently placed hanging lanterns.

The tables were always well-polished and the chairs and booths were cleaned more than regularly. As strict as the manager was, he also cared for the staff, and they cared for each other, as well- in a genuine way that went beyond the relationship between typical employees. No doubt, the Rin of this world felt lucky to be a part of such a tightly knit group.

In one of the booths in the corner closest to the door leading to the employees' changing rooms, Gumi sipped at a cup of tea and patiently, contemplatively watched as Rin disappeared behind aforementioned door.

 _I'll have to say it soon...but what's the best way to bring it up?_

Ideas swam around her head, but none of them seemed to fit the present situation.

 _Hmm...what would Meiko do?_

Meiko would just say it, blunt and straight, regardless of who was around to hear.

 _Then, I should do the opposite._

The door opened, and Rin came out with her purse slung over her shoulder. Gumi stood up, determined.

"Rin-san...there's something really important I need to tell you-" she looked around "-not here though. Come with me."

She grabbed a surprised Rin's wrist and began leading her away. The blonde waved over her shoulder. "Kein-san- I'm clocking out!"

She didn't hear the strict Chinese man's response, but that was fine. If there was trouble, she'd deal with it tomorrow.

Gumi led her up the stairs and straight passed the entrance to the bath house. The entire time, her grip on Rin's hand was firm- gentle but constricting-and though it wasn't physically tight enough to totally keep her from slipping her hand free, Rin had the feeling she wouldn't much like what would happen if she tried.

Gumi took her to a park and then helped her through a nearly hidden passageway strewn with leaves and other fallen branches. They exited into a clearing full of flowers- pink and blue and white and yellow. There was enough shade to be comfortable, but not enough to block out the light of the setting sun. There was a shallow creek flowing by, hidden by the trees, only barely visible as the sunlight sparkled against the top of the murky water.

"This is beautiful..." said Rin softly, not really thinking Gumi could hear her. But she could.

"It is, isn't it? She thought so, too. Thinks so. I think. She said the exact same thing you did." Gumi sighed and let go of Rin's hand, then turned to face her.

"You're not the Kagamine Rin of this world, are you?"

Rin's eyes widened.

 _How did she find out?_

The green-haired girl chuckled.

"That expression looks cute on you," her gaze turned a little harder, "but I'm getting a bit off-topic. You might look similar to her, but I know this world's Rin well enough to spot even the subtle differences. Her eyes are just a tiny bit greener than yours, and her hair's more of a golden blonde- not like that platinum nest of yours at all. But another reason I know is because of this."

She slipped off a golden ring with a simple cross on it.

"I am an apprentice to Meiko the Fate- the controlling force of this universe. I had been with this world's Rin for a while, ever since she found out my secret. But one day, she suddenly appeared in Meiko's domain, saying that she'd been given a small break from this world. I didn't know what she meant at first, but then I saw you, and the pieces clicked."

She was still looking at Rin as she spoke, and the blonde wasn't sure what she was feeling. She herself was apprehensive- what would Gumi do with this information?- but she couldn't tell what Gumi was feeling.

Abruptly, she heard the ringing of tiny bells. They didn't keep her from hearing anything, but they were still very audible. Maybe, a few days prior, she would've been glad to hear them, but not now.

 _Miku's here. That means Luka can't be far behind. But how did they find me so quickly?_

"So, Rin-san. Why are you here? And more importantly, how can I help you finish your business here so you can leave?"

Rin nodded, forcing her focus away from the soft tinkling chimes.

"You have to kill me, Gumi-san. Please, do it quickly now- or else _they_ will catch me."

"Eh? Who's 'they'?"

"The leader of the elves- Luka the Elven Bereth- and Miku the Faerie Queen. They're chasing me to take me back to our homeworld, but it's _imperative_ that I don't let them catch me."

Her eyes locked with Gumi's, pleading, begging her.

"So, you must kill me so I can pass on to the next universe! Please! Before they get here!"

Her voice was urgent. She could hear the gentle hum of magic as Miku and Luka came closer.

Gumi hesitated for a split second before making her decision.

"Alright. Step back for a second. I want this to be as quick and painless as possible."

Rin took a step backwards- towards the bells- and Gumi closed her eyes. She started to glow an emerald green color. Rin felt something slide up her arms and looked down to find that she, too, was glowing that same green. She opened her mouth-

And promptly felt her heart stop. There was a moment- exactly one minute and thirty seconds- of pain. And then, blackness.

 _OooOooOooOooO_

Miku and Luka came upon the clearing just in time to see Rin drop to the ground with a heavy thump. They made to approach her, but Gumi held up her hand and quite literally stopped them in their tracks.

She sniffed.

"You two _reek_ of magic. You must be Miku and Luka, yes?" She said this with a serene smile, as if she hadn't just killed their most precious person.

"Why should we tell _you_!?" Luka snarled. Miku huffed and crossed her arms.

"We _are_ indeed. What business have you with us?" She asked this much more calmly. Gumi shrugged her shoulders and glanced down at Rin's pale body. Unlike other corpses, hers didn't seem to be growing any paler.

"The Rin from your world seems to be running away from you two, and is apparently able to leave a universe through death. But I wonder..." the corpse shuddered "I wonder why she would be so desperate to avoid you..."

The corpse glowed a faint, pulsating green.

Gumi shrugged her shoulders again and knelt down to cradle the glowing body of her Rin.

"I suppose the only one who really knows that is Rin herself though. But perhaps you'll learn on your own sometime." She glanced again at Miku, then at Luka- who was trying unsuccessfully to step closer to her- and then looked back down at Rin. Her hair had grown just a bit darker, and her cheeks were starting to regain color.

Gumi snapped her fingers and a portal materialized behind her.

"Now then, I have somewhere to be. If you love your world's Rin as much as you seem to, you'd best see this world's ruling Fate."

She stood and stepped backwards into the portal.

"She can help you get to the next universe."

The portal closed, and Miku and Luka were left standing alone in the clearing. The sun had only just descended below the horizon, casting a very faint light over everything. Miku took a step forward just in time to hear Luka let out an irritated huff.

"AAGGHHH! _Where_ does that girl get off pulling that kind of crap!? It's not like I was going to actually _do_ anything! Ugh!"

Miku hmphed knowingly.

"Yes you would've, and you know it. Now come along- you can continue your hissy fit on our way to the next universe."

Luka crossed her arms in such a way that her right elbow was above her left, though her right hand stuck out still.

"Fine," she huffed.

She drew a tri-pointed star with her index and middle fingers. Miku mirrored the movement so that they created a sort of hexagram. The fabric of space tore open for them again, and they crossed over into the red void that was Meiko's domain. The portal closed behind them, leaving not even their magical residue behind.

They were again on a white marble staircase.

Miku took a deep, relieved breath. Here, away from all that iron, she felt _much_ more at ease! Luka watched her with a shrug but didn't say anything, choosing instead to start power-walking up the long staircase. With only a moment of pleasantly confused hesitation, Miku followed, her pace equally quick. Very soon, they came to the top where-

 _The Gate_ was already open.

Miku blinked. Luka hummed quizzically.

"So...should we just go through or...?"

Miku shrugged her shoulders and glanced around. Just a few inches to the right of _The Gate_ was what looked like a golden music stand.

"There's a note," the tealette pointed out.

"Let's hear it then," said Luka with a sigh. Miku frowned but read it aloud anyway.

 _To the Fairy and the Elf,_

 _I'm busy, so just go on through_ _ **The Gate**_ _. To apologize for the inconvenience, I've prepared these special McGuffins for you. Just slip'em on and twist the gemstone twice to the left to access the interuniversal go home instantly, turn it three times to the right._

 _There's one for the little girlie you fancy, too._

 _-Meiko_

Behind the note were three rings. They were all silver, but with different, somewhat cylindrically-cut gemstones attached to them with golden braces, running around and over them much like the upper half of a king's crown in chess. The first gem was a not-quite-perfectly cut rhodolite. The second was an almost decagonal piece of blue zircon. The third and final ring had a perfectly cut piece of citrine.

Assuming the teal-bejewelled ring was for her, Miku grabbed the ring with the blue zircon, gingerly passing the rhodolite one to Luka. The citrine one she kept in her subspace pocket.

Luka slipped her ring onto her right ring finger and felt a strange tingling sensation as said ring linked itself to her magical signature.

Miku, having had a similar experience, took a second to collect herself before gesturing towards _The Gate_.

"Shall we?" She bowed mockingly. Luka walked, stopping when she was an arm's length away from Miku.

"We shall."


End file.
